Chucks are used to secure interchangeable bits or heads into a machine. Chucks may secure bits or heads axially and radially to limit unwanted movement during use. Jaw assemblies are one example of a chuck configuration which can be adjusted radially between open and closed positions to secure bits radially. Moving jaws toward the center of the chuck tightens them around the bit or head, securing them for use. Moving the jaws away from the center of the chuck loosens their grip on the bit or head allowing the bit or head to be removed and changed.
To be efficient, the interchange of bits or heads in the chuck must be quick and simple without compromising the secure attachment. Chucks having jaw assemblies may be adjusted by turning an outer housing which engages threads and tightens or loosens the grip of the jaws. This may be time consuming, and if the housing is not turned enough, the bit or head may not be sufficiently secured in the chuck. Alternatively, chucks having jaw assemblies may be adjusted by turning a key in a threaded hole which adjusts each jaw. Again, this may be time consuming and may fail to sufficiently secure the bit or head in the chuck.
Given the above discussion, it would be advantageous to provide an improved apparatus for adjusting a chuck to secure or release a bit or head. It would be advantageous if this apparatus did not require turning a key or a housing so that the chuck could be operated more quickly. It would also be advantageous if this apparatus sufficiently secured the bit or head in the chuck so that a user would be less likely to insufficiently secure the bit or head in the chuck.